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/* ScummVM - Graphic Adventure Engine
*
* ScummVM is the legal property of its developers, whose names
* are too numerous to list here. Please refer to the COPYRIGHT
* file distributed with this source distribution.
*
* This program is free software; you can redistribute it and/or
* modify it under the terms of the GNU General Public License
* as published by the Free Software Foundation; either version 2
* of the License, or (at your option) any later version.
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
* You should have received a copy of the GNU General Public License
* along with this program; if not, write to the Free Software
* Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.
*
* $URL$
* $Id$
*
*/
#include "common/endian.h"
#include "common/file.h"
#include "common/util.h"
#include "common/scummsys.h"
#include "lure/disk.h"
#include "lure/luredefs.h"
#include "lure/res.h"
namespace Lure {
static Disk *int_disk = NULL;
Disk &Disk::getReference() {
return *int_disk;
}
Disk::Disk() {
_fileNum = 0xff;
_fileHandle = NULL;
int_disk = this;
}
Disk::~Disk() {
if (_fileHandle) delete _fileHandle;
int_disk = NULL;
}
uint8 Disk::indexOf(uint16 id, bool suppressError) {
// Make sure the correct file is open - the upper two bits of the Id give the file number. Note
// that an extra check is done for the upper byte of the Id being 0x3f, which is the Id range
// I use for lure.dat resources, which are resources extracted from the lure.exe executable
uint8 entryFileNum = ((id>>8) == 0x3f) ? 0 : ((id >> 14) & 3) + 1;
openFile(entryFileNum);
// Find the correct entry in the list based on the Id
for (int entryIndex=0; entryIndex<NUM_ENTRIES_IN_HEADER; ++entryIndex) {
if (_entries[entryIndex].id == HEADER_ENTRY_UNUSED_ID) break;
else if (_entries[entryIndex].id == id) return entryIndex;
}
if (suppressError) return 0xff;
if (_fileNum == 0)
error("Could not find entry Id #%d in file %s", id, SUPPORT_FILENAME);
else
error("Could not find entry Id #%d in file disk%d.vga", id, _fileNum);
}
void Disk::openFile(uint8 fileNum) {
// Validate that the file number is correct
if (fileNum > 4)
error("Invalid file number specified - %d", fileNum);
// Only load up the new file if the current file number has changed
if (fileNum == _fileNum) return;
// Delete any existing open file handle
if (_fileNum != 0xff) delete _fileHandle;
_fileNum = fileNum;
// Open up the the new file
_fileHandle = new Common::File();
char sFilename[10];
if (_fileNum == 0)
strcpy(sFilename, SUPPORT_FILENAME);
else
sprintf(sFilename, "disk%d.vga", _fileNum);
_fileHandle->open(sFilename);
if (!_fileHandle->isOpen())
error("Could not open %s", sFilename);
// Validate the header
char buffer[7];
uint32 bytesRead;
bytesRead = _fileHandle->read(buffer, 6);
buffer[6] = '\0';
if (strcmp(buffer, HEADER_IDENT_STRING) != 0)
error("The file %s was not a valid VGA file", sFilename);
uint16 fileFileNum = _fileHandle->readUint16BE();
if (fileFileNum != _fileNum)
error("The file %s was not the correct file number", sFilename);
// Read in the header entries
uint32 headerSize = sizeof(FileEntry) * NUM_ENTRIES_IN_HEADER;
if (_fileHandle->read(_entries, headerSize) != headerSize)
error("The file %s had a corrupted header", sFilename);
#ifdef SCUMM_BIG_ENDIAN
// Process the read in header list to convert to big endian
for (int i = 0; i < NUM_ENTRIES_IN_HEADER; ++i) {
_entries[i].id = FROM_LE_16(_entries[i].id);
_entries[i].size = FROM_LE_16(_entries[i].size);
_entries[i].offset = FROM_LE_16(_entries[i].offset);
}
#endif
}
uint32 Disk::getEntrySize(uint16 id) {
// Special room area check
uint16 tempId = id & 0x3fff;
if ((tempId == 0x120) || (tempId == 0x311) || (tempId == 8) || (tempId == 0x410)) {
ValueTableData &fieldList = Resources::getReference().fieldList();
if (fieldList.getField(AREA_FLAG) != 0)
id ^= 0x8000;
}
// Get the index of the resource, if necessary opening the correct file
uint8 index = indexOf(id);
// Calculate the offset and size of the entry
uint32 size = (uint32) _entries[index].size;
if (_entries[index].sizeExtension) size += 0x10000;
return size;
}
MemoryBlock *Disk::getEntry(uint16 id) {
// Special room area check
uint16 tempId = id & 0x3fff;
if ((tempId == 0x120) || (tempId == 0x311) || (tempId == 8) || (tempId == 0x410)) {
ValueTableData &fieldList = Resources::getReference().fieldList();
if (fieldList.getField(AREA_FLAG) != 0)
id ^= 0x8000;
}
// Get the index of the resource, if necessary opening the correct file
uint8 index = indexOf(id);
// Calculate the offset and size of the entry
uint32 size = (uint32) _entries[index].size;
if (_entries[index].sizeExtension) size += 0x10000;
uint32 offset = (uint32) _entries[index].offset * 0x20;
MemoryBlock *result = Memory::allocate(size);
_fileHandle->seek(offset, SEEK_SET);
_fileHandle->read(result->data(), size);
return result;
}
bool Disk::exists(uint16 id) {
// Get the index of the resource, if necessary opening the correct file
uint8 index = indexOf(id, true);
return (index != 0xff);
}
uint8 Disk::numEntries() {
if (_fileNum == 0)
error("No file is currently open");
// Figure out how many entries there are by count until an unused entry is found
for (byte entryIndex = 0; entryIndex < NUM_ENTRIES_IN_HEADER; ++entryIndex)
if (_entries[entryIndex].id == HEADER_ENTRY_UNUSED_ID) return entryIndex;
return NUM_ENTRIES_IN_HEADER;
}
FileEntry *Disk::getIndex(uint8 entryIndex) {
if (_fileNum == 0)
error("No file is currently open");
if ((entryIndex >= NUM_ENTRIES_IN_HEADER) || (_entries[entryIndex].id == HEADER_ENTRY_UNUSED_ID))
error("There is no entry at the specified index");
return &_entries[entryIndex];
}
} // end of namespace Lure
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